Coupling arrangement for components in subsea structures and a remotely operated tool unit for handling such components

Abstract

Interface arrangement for components such as valves and control units incorporated in subsea stations particularly for hydrocarbon production, in which the components during operation are mounted in fixed positions on the subsea station and are adapted to be retrieved therefrom by means of a remotely operated tool unit unit (ROT) havign a mating interface arrangement to cooperate with that of the components. The upper part of the component, which is mounted for retrieval in a substantially vertical direction from its fixed position on the subsea station, is provided with central handling means and one or more coupling members. The handling means and the coupling members are adapted to cooperated with respective mating means and members provided on the ROT. Moreover, the handling means is dimensioned for lifting and transporting the component suspended from the ROT. The coupling members are movable up and down in relation to the handling means, when subjected to substantially vertical pull and push forces, respectively, applied from an ROT in an operative position connection to the component through the handling means, so as to effect an operation on the component, for example locking or unlocking thereof with respect tothe subsea station. The top of the handling means is provided with ports and/or connectors for hydraulic, pneumatic, optical or electric interconnection between the component and an ROT.

We claim: 
     
       1. An interface arrangement, provided on a retrievable component incorporated in a subsea structure, for coupling said component to a mating interface arrangement of a remotely operated tool unit (ROT) which retrieves said component from a fixed position on said subsea structure, said mating interface arrangement of said ROT including a plurality of coupling devices, said interface arrangement comprising: (A) a central handling means, provided on an upper portion of said component, for lifting and transporting said component, said handling means being provided with at least one of ports and connectors, said at least one of ports and connectors providing at least one of hydraulic, pneumatic, optical, and electrical interconnections between said ROT and said component;   (B) a plurality of coupling members which are laterally and symmetrically offset from an axis of said central handling means and which selectively cooperate with said plurality of coupling devices so as to allow said ROT to manipulate said component; and   (C) a yoke member which interconnects said plurality of coupling members so as to allow said plurality of coupling members to be moveable in unison up and down in relation to said handling means when subjected to substantially vertical push and pull forces from said ROT.   
     
     
       2. The arrangement as claimed in claim 1, wherein said plurality of coupling members comprises three coupling members spaced 120° apart about said axis of said handling means. 
     
     
       3. The arrangement as claimed in claim 1, wherein said interface arrangement cooperates with said subsea structure such that said push force causes one of locking said component to said subsea structure and unlocking said component from said subsea structure, and said pull force causes the other of locking said component to said subsea structure and unlocking said component from said subsea structure. 
     
     
       4. The interface arrangement according to claim 1, further comprising connector means for locking and unlocking said component to and from said subsea structure, and a push-pull element which is connected to at least one of said coupling members and which actuates said connector means, said connector means comprising a locking piece which moves laterally when actuated by said push-pull element and which is engaged with and disengaged from a mating locking device on said subsea structure. 
     
     
       5. The interface arrangement according to claim 4, further comprising an inclined cam surface which is provided on one of said push-pull element and said locking piece and which transforms axial movement of said push-pull element into lateral movement of said locking piece. 
     
     
       6. The interface arrangement according to claim 5, wherein said cam surface is provided at such an angle in relation to said axis that said locking piece will remain locked in a position in which it is engaged with said locking device unless it is subjected to said pull force. 
     
     
       7. The interface arrangement according to claim 1, further comprising connector means for locking and unlocking said component to and from said subsea structure, and a plurality of push-pull rods which are larger than said coupling members, which are connected to said coupling members, and which actuate said connector means, said connector means comprising a plurality of locking pieces which move laterally when actuated by a corresponding one of said push-pull rods and which are selectively engaged with and disengaged from mating locking devices on said subsea structure, each of said push-pull rods having a first end which is connected to said yoke member and a second end which actuates the respective one of said locking pieces. 
     
     
       8. A system comprising: (A) a retrievable component which is incorporated in a subsea structure and which has a first interface arrangement provided thereon; and   (B) a remotely operated tool unit (ROT) which retrieves said component from a fixed position on said subsea structure, said ROT having a second interface arrangement for coupling said ROT to said first interface arrangement and for manipulating said component, said second interface arrangement including (i) a central handling connector means for lifting and transporting said component, said central handling connector means having a lower part which is provided with at least one of ports and connectors, said at least one of said ports and said connectors providing at least one of hydraulic, pneumatic, optical, and electrical interconnections between said ROT and said component,   (ii) a plurality of coupling connector members which are laterally and symmetrically offset from an axis of said central handling connector means and which selectively cooperate with said first interface arrangement so as to allow said ROT to manipulate said component, and   (iii) activation means for moving said coupling connector members up and down such that said coupling connector members apply substantially vertical pull and push forces on said component when said ROT is connected to said component through said handling connector means.     
     
     
       9. The system as claimed in claim 8, wherein said plurality of coupling connector members comprises three coupling members spaced 120° apart about said axis of said handling connector means. 
     
     
       10. The system as claimed in claim 8, wherein said activation means comprises a plurality of hydraulic cylinders, each of which is connected to one of said coupling connector members. 
     
     
       11. The system as claimed in claim 8, wherein said ROT comprises a supporting frame,   guide posts, mounted on said supporting frame, for landing said ROT on said subsea structure;   means for controlling and guiding said supporting frame from the surface; and   an elevator which is mounted for vertical movement within said supporting frame and which carries said handling connector means and said coupling connector members.   
     
     
       12. The system according to claim 11, wherein said elevator is capable of travelling to an upper vertical position for retracting said component completely within said supporting frame. 
     
     
       13. The system according to claim 12, further comprising means for securing said elevator in said upper vertical position within said supporting frame so that said component is secured within said supporting frame for transporting. 
     
     
       14. The system according to claim 11, further comprising means for laterally engaging and securing said component to said elevator such that said component is suspended from said elevator and is secured within said supporting frame so that said component can be transported in a secure and protected manner. 
     
     
       15. The system according to claim 11, wherein said elevator is moveable laterally with respect to said axis of said handling connector means when said elevator moves vertically within said frame so as to allow corresponding lateral movement of said component, and further comprising guide means for laterally moving said component with respect to said supporting frame to align said component for mounting on said subsea structure. 
     
     
       16. The system according to claim 11, wherein said guide posts provide a first step of coarse guidance of said component, and further comprising guides which are smaller than said guide posts and which provide a second step of more precise guidance of said component onto a landing area of said subsea structure and which lock said component to said subsea structure. 
     
     
       17. An interface arrangement, provided on a remotely operated tool unit (ROT) which retrieves a component from a fixed position on s subsea structure, for coupling said ROT to a mating interface arrangement on said component and for manipulating said component, said interface arrangement comprising: (A) a central handling connector means for lifting and transporting said component, said central handling connector means having a lower part which is provided with at least one of ports and connectors, said at least one of said ports and said connectors providing at least one of hydraulic, pneumatic, optical, and electrical interconnections between said ROT and said component, and   (B) a plurality of coupling connector members which are laterally and symmetrically offset from an axis of said central handling connector means and which selectively cooperate with said mating interface arrangement of said component so as to allow said ROT to manipulate said component; and   (C) activation means for moving said coupling connector members up and down such that said coupling connector members apply substantially vertical pull and push forces on said component when said ROT is connected to said component through said handling connector means.   
     
     
       18. The interface arrangement as claimed in claim 17, wherein said plurality of coupling connector members comprises three coupling members spaced 120° apart about said axis of said handling connector means. 
     
     
       19. The interface arrangement as claimed in claim 17, wherein said activation means comprises a plurality of hydraulic cylinders, each of which is connected to one of said coupling connector members.